18F-FDG PET/CT in the assessment of carcinoma of unknown primary origin.

Abstract

PURPOSE:

Metastatic cancers of unknown primary origin are characterised by a poor prognosis, with a survival rate from diagnosis of approximately 12 months. Conventional radiological imaging allows detection of 20%-27% of primary cancers, whereas the detection rate with positron emission tomography (PET) is 24%-40%. The aim of this study was to assess the role of 18F-fluorodeoxyglucose (FDG) PET/computed tomography (CT) in the identification of occult primary cancers.

MATERIALS AND METHODS:

The study population consisted of 38 consecutive patients with histologically proven metastatic disease and negative or nonconclusive conventional diagnostic procedures. All patients were studied by 18F-FDG PET performed according to the standard procedure (6 h of fasting, intravenous injection of 370 MBq 18F-FDG, and image acquisition with a PET/CT scanner for 4 min per bed position).

RESULTS:

18F-FDG-PET/CT detected the occult primary cancer in 20 cases (53%), showing higher sensitivity than that reported for any other imaging modality, including PET.

CONCLUSIONS:

The encouraging results, if validated by larger series, support the use of PET/CT in patients with carcinoma of unknown primary origin and negative conventional imaging results.

• Authors: V Ambrosini, C Nanni, D Rubello, A Moretti, G Battista, P Castellucci, M Farsad, L Rampin, G Fiorentini, R Franchi, R Canini, S Fanti
• Journal: La Radiologia medica (Radiol Med) Vol. 111 Issue 8 Pg. 1146-55 (Dec 2006) ISSN: 0033-8362 [Print] Italy
• PMID: 17171520 (Publication Type: Journal Article)

Chemical References

• Radiopharmaceuticals
• Fluorodeoxyglucose F18

Topics

• Adult
• Aged
• Aged, 80 and over
• Carcinoma (diagnosis, diagnostic imaging, secondary)
• Female
• Fluorodeoxyglucose F18
• Humans
• Male
• Middle Aged
• Neoplasms, Unknown Primary (diagnosis, diagnostic imaging)
• Positron-Emission Tomography (methods)
• Prognosis
• Radiopharmaceuticals
• Reproducibility of Results
• Sensitivity and Specificity
• Tomography, X-Ray Computed